Resonant Inspection of Nodularity

Abstract

One common application for RAM-NDT is testing ductile iron for acceptable levels of nodularity. Cast iron is a metal alloy characterized by relatively high carbon content. During the metal’s solidification, this carbon content can form graphite, with tiny, irregular flakes that disrupt the crystalline structure, causing cracks and unwanted brittleness. In ductile iron the graphite forms spherical, rounded nodules that inhibit the formation of cracks and provide enhanced ductility and machinability.